Cheers!
I have little experience with av recievers. My previous one was a Pioneer VSX1016, which I bought second hand and turned out to be faulty! Performance wise, I think the Onkyo (which is less powerful and further down its respective range) beats the Pioneer comfortably. The PCM track on Ratatouille for example, is jawdropping through the 576. Again though, my experience of HD audio is limited and my ability to discern the difference won't be as finely tuned as you guys.
Surprisingly, I'm pretty impressed with the 576's musical performance. It is a beautiful listen (WMA tracks stored on the ps3) when coupled with my Q1010is.
Basically, the 576 is perfectly suited to my PS3/ 1010i set up. I'm amazed at what it can do for the price (LPCM via HDMI!) and think anyone with a similar set up to me should seriously consider it (notwithstanding the new budget Sony of course!).